[@The One]

I acknowledge that it's possible but its not in keeping with the general gist of the RP, its idea and aims.

In terms of backstory, although there is no such thing as 'normal' they should have led a relatively 'normal' or 'mainstream' life.  That does not mean that it should be bland and that it can't be unique. simply that it should be relevant.  Other character sheets posted so far have a good grasp and show a decent variety of character backgrounds, it may be worth looking over them for examples and inspiration.